The -nostdlib option requests the compiler to not use the standard
system startup files or libraries when linking. It is effective only
when $(CC) is used as a linker driver.
Since commit 691efbedc6 ("arm64: vdso: use $(LD) instead of $(CC)
to link VDSO"), $(LD) is directly used, hence -nostdlib is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20211107161802.323125-1-masahiroy@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The id argument of ARM64_FTR_REG_OVERRIDE() is used for two purposes:
one as the system register encoding (used for the sys_id field of
__ftr_reg_entry), and the other as the register name (stringified
and used for the name field of arm64_ftr_reg), which is debug
information. The id argument is supposed to be a macro that
indicates an encoding of the register (eg. SYS_ID_AA64PFR0_EL1, etc).
ARM64_FTR_REG(), which also has the same id argument,
uses ARM64_FTR_REG_OVERRIDE() and passes the id to the macro.
Since the id argument is completely macro-expanded before it is
substituted into a macro body of ARM64_FTR_REG_OVERRIDE(),
the stringified id in the body of ARM64_FTR_REG_OVERRIDE is not
a human-readable register name, but a string of numeric bitwise
operations.
Fix this so that human-readable register names are available as
debug information.
Fixes: 8f266a5d87 ("arm64: cpufeature: Add global feature override facility")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211101045421.2215822-1-reijiw@google.com
Signed-off-by: Will Deacon <will@kernel.org>
* for-next/vdso:
arm64: vdso32: require CROSS_COMPILE_COMPAT for gcc+bfd
arm64: vdso32: suppress error message for 'make mrproper'
arm64: vdso32: drop test for -march=armv8-a
arm64: vdso32: drop the test for dmb ishld
* for-next/trbe-errata:
arm64: errata: Add detection for TRBE write to out-of-range
arm64: errata: Add workaround for TSB flush failures
arm64: errata: Add detection for TRBE overwrite in FILL mode
arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
* for-next/sve:
arm64/sve: Fix warnings when SVE is disabled
arm64/sve: Add stub for sve_max_virtualisable_vl()
arm64/sve: Track vector lengths for tasks in an array
arm64/sve: Explicitly load vector length when restoring SVE state
arm64/sve: Put system wide vector length information into structs
arm64/sve: Use accessor functions for vector lengths in thread_struct
arm64/sve: Rename find_supported_vector_length()
arm64/sve: Make access to FFR optional
arm64/sve: Make sve_state_size() static
arm64/sve: Remove sve_load_from_fpsimd_state()
arm64/fp: Reindent fpsimd_save()
* for-next/kexec:
arm64: trans_pgd: remove trans_pgd_map_page()
arm64: kexec: remove cpu-reset.h
arm64: kexec: remove the pre-kexec PoC maintenance
arm64: kexec: keep MMU enabled during kexec relocation
arm64: kexec: install a copy of the linear-map
arm64: kexec: use ld script for relocation function
arm64: kexec: relocate in EL1 mode
arm64: kexec: configure EL2 vectors for kexec
arm64: kexec: pass kimage as the only argument to relocation function
arm64: kexec: Use dcache ops macros instead of open-coding
arm64: kexec: skip relocation code for inplace kexec
arm64: kexec: flush image and lists during kexec load time
arm64: hibernate: abstract ttrb0 setup function
arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors
arm64: kernel: add helper for booted at EL2 and not VHE
In configurations where SVE is disabled we define but never reference the
functions for retrieving the default vector length, causing warnings. Fix
this by move the ifdef up, marking get_default_vl() inline since it is
referenced from code guarded by an IS_ENABLED() check, and do the same for
the other accessors for consistency.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211022141635.2360415-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Arm Neoverse-N2 and Cortex-A710 cores are affected by an erratum where
the trbe, under some circumstances, might write upto 64bytes to an
address after the Limit as programmed by the TRBLIMITR_EL1.LIMIT.
This might -
- Corrupt a page in the ring buffer, which may corrupt trace from a
previous session, consumed by userspace.
- Hit the guard page at the end of the vmalloc area and raise a fault.
To keep the handling simpler, we always leave the last page from the
range, which TRBE is allowed to write. This can be achieved by ensuring
that we always have more than a PAGE worth space in the range, while
calculating the LIMIT for TRBE. And then the LIMIT pointer can be
adjusted to leave the PAGE (TRBLIMITR.LIMIT -= PAGE_SIZE), out of the
TRBE range while enabling it. This makes sure that the TRBE will only
write to an area within its allowed limit (i.e, [head-head+size]) and
we do not have to handle address faults within the driver.
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211019163153.3692640-5-suzuki.poulose@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Arm Neoverse-N2 (#2067961) and Cortex-A710 (#2054223) suffers
from errata, where a TSB (trace synchronization barrier)
fails to flush the trace data completely, when executed from
a trace prohibited region. In Linux we always execute it
after we have moved the PE to trace prohibited region. So,
we can apply the workaround every time a TSB is executed.
The work around is to issue two TSB consecutively.
NOTE: This errata is defined as LOCAL_CPU_ERRATUM, implying
that a late CPU could be blocked from booting if it is the
first CPU that requires the workaround. This is because we
do not allow setting a cpu_hwcaps after the SMP boot. The
other alternative is to use "this_cpu_has_cap()" instead
of the faster system wide check, which may be a bit of an
overhead, given we may have to do this in nvhe KVM host
before a guest entry.
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211019163153.3692640-4-suzuki.poulose@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Arm Neoverse-N2 and the Cortex-A710 cores are affected
by a CPU erratum where the TRBE will overwrite the trace buffer
in FILL mode. The TRBE doesn't stop (as expected in FILL mode)
when it reaches the limit and wraps to the base to continue
writing upto 3 cache lines. This will overwrite any trace that
was written previously.
Add the Neoverse-N2 erratum(#2139208) and Cortex-A710 erratum
(#2119858) to the detection logic.
This will be used by the TRBE driver in later patches to work
around the issue. The detection has been kept with the core
arm64 errata framework list to make sure :
- We don't duplicate the framework in TRBE driver
- The errata detection is advertised like the rest
of the CPU errata.
Note that the Kconfig entries are not fully active until the
TRBE driver implements the work around.
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
cc: Leo Yan <leo.yan@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211019163153.3692640-3-suzuki.poulose@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
We no longer place anything into a `.fixup` section, so we no longer
need to place those sections into the `.text` section in the main kernel
Image.
Remove the use of `.fixup`.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-14-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
For inline assembly, we place exception fixups out-of-line in the
`.fixup` section such that these are out of the way of the fast path.
This has a few drawbacks:
* Since the fixup code is anonymous, backtraces will symbolize fixups as
offsets from the nearest prior symbol, currently
`__entry_tramp_text_end`. This is confusing, and painful to debug
without access to the relevant vmlinux.
* Since the exception handler adjusts the PC to execute the fixup, and
the fixup uses a direct branch back into the function it fixes,
backtraces of fixups miss the original function. This is confusing,
and violates requirements for RELIABLE_STACKTRACE (and therefore
LIVEPATCH).
* Inline assembly and associated fixups are generated from templates,
and we have many copies of logically identical fixups which only
differ in which specific registers are written to and which address is
branched to at the end of the fixup. This is potentially wasteful of
I-cache resources, and makes it hard to add additional logic to fixups
without significant bloat.
This patch address all three concerns for inline uaccess fixups by
adding a dedicated exception handler which updates registers in
exception context and subsequent returns back into the function which
faulted, removing the need for fixups specialized to each faulting
instruction.
Other than backtracing, there should be no functional change as a result
of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-12-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup and BPF handlers we have today. In preparation,
this patch adds a new `type` field to struct exception_table_entry, and
uses this to distinguish the fixup and BPF cases. A `data` field is also
added so that subsequent patches can associate data specific to each
exception site (e.g. register numbers).
Handlers are named ex_handler_*() for consistency, following the exmaple
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions ins subsequent
patches.
This patch will increase the size of the exception tables, which will be
remedied by subsequent patches removing redundant fixup code. There
should be no functional change as a result of this patch.
Since each entry is now 12 bytes in size, we must reduce the alignment
of each entry from `.align 3` (i.e. 8 bytes) to `.align 2` (i.e. 4
bytes), which is the natrual alignment of the `insn` and `fixup` fields.
The current 8-byte alignment is a holdover from when the `insn` and
`fixup` fields was 8 bytes, and while not harmful has not been necessary
since commit:
6c94f27ac8 ("arm64: switch to relative exception tables")
Similarly, RO_EXCEPTION_TABLE_ALIGN is dropped to 4 bytes.
Concurrently with this patch, x86's exception table entry format is
being updated (similarly to a 12-byte format, with 32-bytes of absolute
data). Once both have been merged it should be possible to unify the
sorttable logic for the two.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: James Morse <james.morse@arm.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-11-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Similar to
commit 231ad7f409 ("Makefile: infer --target from ARCH for CC=clang")
There really is no point in setting --target based on
$CROSS_COMPILE_COMPAT for clang when the integrated assembler is being
used, since
commit ef94340583 ("arm64: vdso32: drop -no-integrated-as flag").
Allows COMPAT_VDSO to be selected without setting $CROSS_COMPILE_COMPAT
when using clang and lld together.
Before:
$ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig
$ grep CONFIG_COMPAT_VDSO .config
CONFIG_COMPAT_VDSO=y
$ ARCH=arm64 make -j72 LLVM=1 defconfig
$ grep CONFIG_COMPAT_VDSO .config
$
After:
$ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig
$ grep CONFIG_COMPAT_VDSO .config
CONFIG_COMPAT_VDSO=y
$ ARCH=arm64 make -j72 LLVM=1 defconfig
$ grep CONFIG_COMPAT_VDSO .config
CONFIG_COMPAT_VDSO=y
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20211019223646.1146945-5-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
When running the following command without arm-linux-gnueabi-gcc in
one's $PATH, the following warning is observed:
$ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 mrproper
make[1]: arm-linux-gnueabi-gcc: No such file or directory
This is because KCONFIG is not run for mrproper, so CONFIG_CC_IS_CLANG
is not set, and we end up eagerly evaluating various variables that try
to invoke CC_COMPAT.
This is a similar problem to what was observed in
commit dc960bfeed ("h8300: suppress error messages for 'make clean'")
Reported-by: Lucas Henneman <henneman@google.com>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20211019223646.1146945-4-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
Binutils added support for this instruction in commit
e797f7e0b2bedc9328d4a9a0ebc63ca7a2dbbebc which shipped in 2.24 (just
missing the 2.23 release) but was cherry-picked into 2.23 in commit
27a50d6755bae906bc73b4ec1a8b448467f0bea1. Thanks to Christian and Simon
for helping me with the patch archaeology.
According to Documentation/process/changes.rst, the minimum supported
version of binutils is 2.23. Since all supported versions of GAS support
this instruction, drop the assembler invocation, preprocessor
flags/guards, and the cross assembler macro that's now unused.
This also avoids a recursive self reference in a follow up cleanup
patch.
Cc: Christian Biesinger <cbiesinger@google.com>
Cc: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20211019223646.1146945-2-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
As for SVE we will track a per task SME vector length for tasks. Convert
the existing storage for the vector length into an array and update
fpsimd_flush_task() to initialise this in a function.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently when restoring the SVE state we supply the SVE vector length
as an argument to sve_load_state() and the underlying macros. This becomes
inconvenient with the addition of SME since we may need to restore any
combination of SVE and SME vector lengths, and we already separately
restore the vector length in the KVM code. We don't need to know the vector
length during the actual register load since the SME load instructions can
index into the data array for us.
Refactor the interface so we explicitly set the vector length separately
to restoring the SVE registers in preparation for adding SME support, no
functional change should be involved.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-9-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
With the introduction of SME we will have a second vector length in the
system, enumerated and configured in a very similar fashion to the
existing SVE vector length. While there are a few differences in how
things are handled this is a relatively small portion of the overall
code so in order to avoid code duplication we factor out
We create two structs, one vl_info for the static hardware properties
and one vl_config for the runtime configuration, with an array
instantiated for each and update all the users to reference these. Some
accessor functions are provided where helpful for readability, and the
write to set the vector length is put into a function since the system
register being updated needs to be chosen at compile time.
This is a mostly mechanical replacement, further work will be required
to actually make things generic, ensuring that we handle those places
where there are differences properly.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-8-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
In a system with SME there are parallel vector length controls for SVE and
SME vectors which function in much the same way so it is desirable to
share the code for handling them as much as possible. In order to prepare
for doing this add a layer of accessor functions for the various VL related
operations on tasks.
Since almost all current interactions are actually via task->thread rather
than directly with the thread_info the accessors use that. Accessors are
provided for both generic and SVE specific usage, the generic accessors
should be used for cases where register state is being manipulated since
the registers are shared between streaming and regular SVE so we know that
when SME support is implemented we will always have to be in the appropriate
mode already and hence can generalise now.
Since we are using task_struct and we don't want to cause widespread
inclusion of sched.h the acessors are all out of line, it is hoped that
none of the uses are in a sufficiently critical path for this to be an
issue. Those that are most likely to present an issue are in the same
translation unit so hopefully the compiler may be able to inline anyway.
This is purely adding the layer of abstraction, additional work will be
needed to support tasks using SME.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The function has SVE specific checks in it and it will be more trouble
to add conditional code for SME than it is to simply rename it to be SVE
specific.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-6-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
SME introduces streaming SVE mode in which FFR is not present and the
instructions for accessing it UNDEF. In preparation for handling this
update the low level SVE state access functions to take a flag specifying
if FFR should be handled. When saving the register state we store a zero
for FFR to guard against uninitialized data being read. No behaviour change
should be introduced by this patch.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Following optimisations of the SVE register handling we no longer load the
SVE state from a saved copy of the FPSIMD registers, we convert directly
in registers or from one saved state to another. Remove the function so we
don't need to update it during further refactoring.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently all the active code in fpsimd_save() is inside a check for
TIF_FOREIGN_FPSTATE. Reduce the indentation level by changing to return
from the function if TIF_FOREIGN_FPSTATE is set.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Since userspace can make use of the CNTVSS_EL0 instruction, expose
it via a HWCAP.
Suggested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-18-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Since CNTVCTSS obey the same control bits as CNTVCT, add the necessary
decoding to the hook table. Note that there is no known user of
this at the moment.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-17-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Add a new capability to detect the Enhanced Counter Virtualization
feature (FEAT_ECV).
Reviewed-by: Oliver Upton <oupton@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-15-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
MTE provides an asymmetric mode for detecting tag exceptions. In
particular, when such a mode is present, the CPU triggers a fault
on a tag mismatch during a load operation and asynchronously updates
a register when a tag mismatch is detected during a store operation.
Add support for MTE asymmetric mode.
Note: If the CPU does not support MTE asymmetric mode the kernel falls
back on synchronous mode which is the default for kasan=on.
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20211006154751.4463-5-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Add the cpufeature entries to detect the presence of Asymmetric MTE.
Note: The tag checking mode is initialized via cpu_enable_mte() ->
kasan_init_hw_tags() hence to enable it we require asymmetric mode
to be at least on the boot CPU. If the boot CPU does not have it, it is
fine for late CPUs to have it as long as the feature is not enabled
(ARM64_CPUCAP_BOOT_CPU_FEATURE).
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211006154751.4463-4-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
This header contains only cpu_soft_restart() which is never used directly
anymore. So, remove this header, and rename the helper to be
cpu_soft_restart().
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-15-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Now that kexec does its relocations with the MMU enabled, we no longer
need to clean the relocation data to the PoC.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-14-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Now, that we have linear map page tables configured, keep MMU enabled
to allow faster relocation of segments to final destination.
Cavium ThunderX2:
Kernel Image size: 38M Iniramfs size: 46M Total relocation size: 84M
MMU-disabled:
relocation 7.489539915s
MMU-enabled:
relocation 0.03946095s
Broadcom Stingray:
The performance data: for a moderate size kernel + initramfs: 25M the
relocation was taking 0.382s, with enabled MMU it now takes
0.019s only or x20 improvement.
The time is proportional to the size of relocation, therefore if initramfs
is larger, 100M it could take over a second.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-13-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
To perform the kexec relocation with the MMU enabled, we need a copy
of the linear map.
Create one, and install it from the relocation code. This has to be done
from the assembly code as it will be idmapped with TTBR0. The kernel
runs in TTRB1, so can't use the break-before-make sequence on the mapping
it is executing from.
The makes no difference yet as the relocation code runs with the MMU
disabled.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-12-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, relocation code declares start and end variables
which are used to compute its size.
The better way to do this is to use ld script, and put relocation
function in its own section.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-11-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Since we are going to keep MMU enabled during relocation, we need to
keep EL1 mode throughout the relocation.
Keep EL1 enabled, and switch EL2 only before entering the new world.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-10-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
If we have a EL2 mode without VHE, the EL2 vectors are needed in order
to switch to EL2 and jump to new world with hypervisor privileges.
In preparation to MMU enabled relocation, configure our EL2 table now.
Kexec uses #HVC_SOFT_RESTART to branch to the new world, so extend
el1_sync vector that is provided by trans_pgd_copy_el2_vectors() to
support this case.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-9-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, kexec relocation function (arm64_relocate_new_kernel) accepts
the following arguments:
head: start of array that contains relocation information.
entry: entry point for new kernel or purgatory.
dtb_mem: first and only argument to entry.
The number of arguments cannot be easily expended, because this
function is also called from HVC_SOFT_RESTART, which preserves only
three arguments. And, also arm64_relocate_new_kernel is written in
assembly but called without stack, thus no place to move extra arguments
to free registers.
Soon, we will need to pass more arguments: once we enable MMU we
will need to pass information about page tables.
Pass kimage to arm64_relocate_new_kernel, and teach it to get the
required fields from kimage.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-8-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
kexec does dcache maintenance when it re-writes all memory. Our
dcache_by_line_op macro depends on reading the sanitized DminLine
from memory. Kexec may have overwritten this, so open-codes the
sequence.
dcache_by_line_op is a whole set of macros, it uses dcache_line_size
which uses read_ctr for the sanitsed DminLine. Reading the DminLine
is the first thing the dcache_by_line_op does.
Rename dcache_by_line_op dcache_by_myline_op and take DminLine as
an argument. Kexec can now use the slightly smaller macro.
This makes up-coming changes to the dcache maintenance easier on
the eye.
Code generated by the existing callers is unchanged.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-7-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
In case of kdump or when segments are already in place the relocation
is not needed, therefore the setup of relocation function and call to
it can be skipped.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Suggested-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-6-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, during kexec load we are copying relocation function and
flushing it. However, we can also flush kexec relocation buffers and
if new kernel image is already in place (i.e. crash kernel), we can
also flush the new kernel image itself.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-5-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently, only hibernate sets custom ttbr0 with safe idmaped function.
Kexec, is also going to be using this functionality when relocation code
is going to be idmapped.
Move the setup sequence to a dedicated cpu_install_ttbr0() for custom
ttbr0.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-4-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Users of trans_pgd may also need a copy of vector table because it is
also may be overwritten if a linear map can be overwritten.
Move setup of EL2 vectors from hibernate to trans_pgd, so it can be
later shared with kexec as well.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-3-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Replace places that contain logic like this:
is_hyp_mode_available() && !is_kernel_in_hyp_mode()
With a dedicated boolean function is_hyp_nvhe(). This will be needed
later in kexec in order to sooner switch back to EL2.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-2-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
It is not necessary to write to GCR_EL1 on every kernel entry and
exit when HW tag-based KASAN is disabled because the kernel will not
execute any IRG instructions in that mode. Since accessing GCR_EL1
can be expensive on some microarchitectures, avoid doing so by moving
the access to task switch when HW tag-based KASAN is disabled.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://linux-review.googlesource.com/id/I78e90d60612a94c24344526f476ac4ff216e10d2
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210924010655.2886918-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
Annotating a pointer from kernel to __user and then back again requires
an extra __force annotation to silent sparse warning. In call_undef_hook()
this unnecessary complexity can be avoided by modifying the intermediate
user pointer to unsigned long.
This way there is no inter-changeable use of user and kernel pointers
and the code is consistent.
Note: This patch adds no functional changes to code.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210917055811.22341-1-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
